Agent-based models have been an emerging approach in epidemiological modelling, specifically in i... more Agent-based models have been an emerging approach in epidemiological modelling, specifically in investigating the COVID-19 virus. However, there are challenges to its validation due to the absence of real data on specific socioeconomic and cognitive aspects. Therefore, this work aims to present a strategy for updating, verifying and validating these models based on applying the particle swarm optimization algorithm to better model a real case. For such application, this work also presents a new framework based on multi-agents that allowed estimating the evolution of the pandemic, predicting hospital resources, and estimating adaptive population immunization and population density in specific areas. Evaluation metrics such as the data's Shape Factor (SF), Mean Square Error (RMSE), and statistical and sensitivity analyses of the responses obtained were applied for comparison with the real data. The Brazilian municipality of Passa Vinte, located in the State of Minas Gerais (MG), was used as a case study. The model was updated in cumulative cases until the 365th day of the pandemic. The results obtained in the statistical and sensitivity analysis showed similar patterns around the actual data up to the 500th day of the pandemic. Their mean values of SF and RMSE were 0.96 and 7.22, respectively, showing good predictability and consistency, serving as an adequate tool for decision-making in health policies.
Anais do ... Simpósio Brasileiro de Automação Inteligente, 2021
Radio frequency identification systems are used in several applications for the unique recognitio... more Radio frequency identification systems are used in several applications for the unique recognition of objects. Due to the remote communication, malicious agents can read, alter and copy the transmitted information to damage the system. Therefore, researchers have created several protocols to protect these communications employing cryptographic techniques. Recently, Baashirah and Abuzneid proposed a serverless RFID authentication protocol (SLEC) based on elliptic curve cryptography to secure communication in RFID systems. Nevertheless, it has security vulnerabilities and its scalability is faulty. This work presents a comprehensive analysis that discusses the State of the Art of cryptographic applications in RFID systems and points out the SLEC protocol security and scalability issues.
A minimização do consumo de energia em redes Ad-Hoc constitui uma grande preocupação para os admi... more A minimização do consumo de energia em redes Ad-Hoc constitui uma grande preocupação para os administradores desse tipo de rede. Com a disponibilidade cada vez maior de recursos de redes, as operações que envolvem os conceitos de Comando e Controle, sejam civis ou militares, podem cada vez mais se beneficiar desse tipo de estudo. Este trabalho apresenta uma revisão bibliográfica dos principais conceitos de redes de comando e controle, bem como sobre o consumo de energia em redes Ad-Hoc, que são bastante utilizadas nesse tipo de ambiente.
Agent-based models have been an emerging approach in epidemiological modelling, specifically in i... more Agent-based models have been an emerging approach in epidemiological modelling, specifically in investigating the COVID-19 virus. However, there are challenges to its validation due to the absence of real data on specific socioeconomic and cognitive aspects. Therefore, this work aims to present a strategy for updating, verifying and validating these models based on applying the particle swarm optimization algorithm to better model a real case. For such application, this work also presents a new framework based on multi-agents, whose significant contribution consists of forecasting needed hospital resources, population adaptative immunization and reports concerning demographic density, including physical and socioeconomic aspects of a real society in the modelling task. Evaluation metrics such as the data's Shape Factor (SF), Mean Square Error (RMSE), and statistical and sensitivity analyses of the responses obtained were applied for comparison with the real data. The Brazilian municipality of Passa Vinte, located in the State of Minas Gerais (MG), was used as a case study. The model was updated in cumulative cases until the 365th day of the pandemic. The statistical and sensitivity analysis results showed similar patterns around the actual data up to the 500th day of the pandemic. Their mean values of SF and RMSE were 0.96 and 7.22, respectively, showing good predictability and consistency, serving as an adequate tool for decision-making in health policies. Multi-agent-based models have aroused the interest of many researchers in several applications. Its approach consists of a method for analyzing "complex social systems" characterized by multiple interacting parts and may present non-linear behaviours. Policymakers and researchers have applied these models exhaustively, seeking answers to epidemiologic and biological issues. For instance, to investigate the effects of a given pathogen on society and the human body, experimental testing conditions would put the safety of people at risk, creating ethical problems and/or biological disasters. Thus, multi-agent models consist of autonomous agents who work toward goals (as opposed to discrete tasks) in a dynamic environment (where change is the norm), without continuous direct supervision or control, and exhibit a significant degree of flexibility 6. Therefore, the multi-agent approach becomes a reasonable and suitable proposal for modelling due to the variety of effects caused by the Severe Acute Respiratory Syndrome-2 (SARS-CoV-2) virus in the human body and society Corona Virus Disease (COVID-19) spreading. However, it is worth mentioning the following question: how may these models be evaluated and validated? Using multi-agent models to model real-world and social systems has attracted criticism due to the challenges involved in their validation 20. This work studied an intra-state conflict multi-agent-based model to give a balanced perspective on those criticisms. Indeed, multi-agent models for social systems are most useful when the connection between micro-behaviours and macro-behaviours is not well-understood. Another point is when data collection from the real-world system is prohibitively expensive for time or money or if it puts human lives at risk. Despite the criticisms regarding agent-based models, this approach is advantageous when agents are heterogeneous, and the heterogeneity of the agents affects the overall performance of the system. Also, these models provide more detailed information than equation-based models or many other approaches. These agents' interactions are frequently non-linear, changing both spatially and temporally. The emphasis is on modelling, capturing, and replicating new emergent properties in a complex system of individual components that evolve
Anais do XIV Simpósio Brasileiro de Computação Ubíqua e Pervasiva (SBCUP 2022)
Radio frequency identification systems are widely used to uniquely identify objects in many appli... more Radio frequency identification systems are widely used to uniquely identify objects in many applications such as magnetic cards, security tags, and logistic management systems. Despite these advantages provided by the RFID system, there remain a multitude of security concerns related to spoofing and espionage that are all concerned with radio frequency interception. Current research analysis is promising, particularly the work of Ibrahim and Dalkiliç. Their findings are, however, limited by the amount of tags that can be processed—which under certain circumstances can exhaust the server. We designed our new protocol and conducted a performance analysis. When compared to the Ibrahim and Dalkiliç's protocol, our results revealed a drastic reduction in the communication cost that was proportional to the amount of tags authenticated. Once the results were tallied, we modeled our proposed protocol in a discrete event simulation. As a proof of concept, our protocol was then implemente...
Anais do XXV Simpósio Brasileiro de Telecomunicações, 2007
Resumo-Este trabalho estuda os problemas decorrentes da coexistência dos fluxos TCP e UDP em rede... more Resumo-Este trabalho estuda os problemas decorrentes da coexistência dos fluxos TCP e UDP em redes de dados, tendo em vista o observado aumento do volume de tráfego transportado via UDP nosúltimos anos. Nossa propostaé que os fluxos UDP, por não serem cooperativos, sejam penalizados via tarifação de acordo com o impacto causado no tráfego TCP. Algoritmos de controle de admissão e roteamento são propostos de forma a regularem o tráfego UDP minimizando o estrangulamento do TCP e garantindo também a QoS necessária aos fluxos UDP. Resultados da simulação mostram as vantagens da proposta quando comparada com o cenário atual da Internet. Palavras-Chave-qualidade de serviço, coexistência TCP-UDP, controle de congestionamento, controle de admissão, função utilidade Abstract-This work studies the coexistence of TCP and UDP flows in data networks. Our proposal is that UDP flows are penalized, through a dynamic charging scheme, according to the impact caused on TCP traffic. Admission control and routing algorithms are proposed to regulate UDP traffic minimizing TCP starvation and providing the required QoS for UDP flows. Simulation results show the advantage of our proposal when compared to current procedures in the Internet scenario.
Journal of Communications and Networks, Dec 1, 2021
Disruption tolerant networks (DTN) are an evolution of mobile adhoc networks (MANET) working in s... more Disruption tolerant networks (DTN) are an evolution of mobile adhoc networks (MANET) working in scenarios where nodes are sparsely distributed, with low density, connections are intermittent and end-to-end infrastructure is not accessible. Therefore, DTNs are recommended for high latency applications that can last from hours to days. The maritime scenario has characteristics that would justify the use of DTN networks, but the concern with data security is also a relevant aspect in such scenarios. Thus, this paper proposes to evaluate the DTN approach in the maritime Scenario involving warships and helicopters, for sending tactical messages, taking into consideration security aspects at the perimeters where contacts occur. We set up a simulation experiment to compare the performance of Epidemic, Spray and Wait, and Direct Delivery protocols in three scenarios with different sizes. We also propose the application of discriminant analysis as a classification technique to select secure connections to improve the security of the DTN architecture.
Even after nearly two decades of the creation of the first botnet, the detection and mitigation o... more Even after nearly two decades of the creation of the first botnet, the detection and mitigation of their attacks remain one of the biggest challenges faced by researchers and cyber-security professionals. Although there are numerous studies related to botnet detection, estimating how much one method is better than another is still an open problem, mainly because of the difficulty in comparing and reproducing such methods. This work proposes an architecture, implemented with Spark as a high-performance data processing solution, together with VisTrails as a workflow management and data provenance solution, to address this comparability and reproducibility problem in a large-scale environment, as well as a tool, ProvTracker, to analyze and compare the methods results. Another contribution is on the way to couple these two technologies so that intermediary data is maintained available during several partial (re)executions of the experiments involved in each method, minimizing the impact...
Anais Estendidos do XXII Simpósio Brasileiro de Segurança da Informação e de Sistemas Computacionais (SBSeg Estendido 2022)
O BGP e vital para a interligação dos Sistemas Autônomos da Internet, e o número de ataques de se... more O BGP e vital para a interligação dos Sistemas Autônomos da Internet, e o número de ataques de sequestro de prefixos vem aumentando. Entre as soluções discutidas na literatura, o RPKI vem sendo a opção preferencial. O objetivo deste trabalho é o de validar o RPKI, através de testes de robustez a ataques de Prefix Hijacking. Os resultados foram satisfatórios, uma vez que a solução permitiu identificar as rotas não autenticadas. Porém, durante a pesquisa, foi identificado e testado um recurso do RPKI passível de ser usado em ataques, o SLURM FILE. Não foram encontrados trabalhos abordando essa possibilidade, sendo esta a principal contribuicão da dissertação.
Anais do XII Simpósio Brasileiro de Segurança da Informação e de Sistemas Computacionais (SBSeg 2012)
Este trabalho tem por objetivo apresentar uma proposta de arquitetura para um sistema de defesa c... more Este trabalho tem por objetivo apresentar uma proposta de arquitetura para um sistema de defesa cibernética capaz de detecar bots e bloquear a comunicação entre os bots e as botnets. Também é proposto um algoritmo de detecção de bots baseado em grafos de relacionamento. Foram realizados experimentos por meio da análise de registros de consultas DNS com o objetivo de encontrar máquinas suspeitas de serem zumbis. Resultados preliminares mostram que os mecanismos empregados permitem filtrar os registros de DNS e identificar máquinas suspeitas de pertencerem a uma botnet.
This paper presents an application and adaptation of the epidemiological model known as Susceptib... more This paper presents an application and adaptation of the epidemiological model known as Susceptible-Infected- Recovered to the mathematical modeling of the process of message forwarding in a Delay-Tolerant Network scenario char- acterized by epidemic routing. Simulation results are compared to the mathematical model indicating a good fit of the approach.
Anais do XXV Simpósio Brasileiro de Telecomunicações, 2007
Scheduling mechanisms for critical operations over low performance wireless networks use of prior... more Scheduling mechanisms for critical operations over low performance wireless networks use of priorities to guarantee to the most valuable information the available communication resources to accomplish the mission. A traditional way to implement that is to use strict precedence levels, however such naive scheme has several side effects. We propose a multiple criteria decision approach which takes into account several parameters to make a decision. A lexicographic algorithm and an algorithm based on the barrier function are also proposed. Simulation results confirm the advantages on using our approach over traditional methods. Resumo-Os algoritmos de escalonamento de mensagens para operações críticas sobre redes sem fio de baixo desempenho priorizam as mensagens a fim de garantir que a informação mais importante tenha os recursos suficientes para ser enviada. A forma tradicional de se implementar prioridadesé através do emprego de filas de prioridades, contudo este esquema apresenta várias desvantagens. O artigo propõe dois algoritmos multicritério para a realização do escalonamento das mensagens: o primeiro baseado na ordenação lexicográfica e o segundo no uso de funções barreira. Resultados de simulação confirmam o bom desempenho de nossas propostas em comparação com os algoritmos tradicionais.
2018 Workshop on Metrology for Industry 4.0 and IoT, 2018
Reference datasets are databases that guide the development and the evaluation of tools and metho... more Reference datasets are databases that guide the development and the evaluation of tools and methods in several areas of Computer Science. In the field of Information Security, in particular, there is a notable need for tools devoted to detection and classification. Hence, the availability of such datasets is fundamental: the reference dataset is seen as a standard against which a tool must be tested characterize its accuracy. In this sense, the reference dataset is analogous to the classic metrology primary standard, in a sense that it provides the most trustworthy reference against which an object under evaluation can be compared to. It is therefore of great importance to devote efforts to the development of methods that assure the quality of reference datasets. In the present work, we discuss the challenges faced by the currently available datasets and propose directions towards the development of reliable datasets. Finally, we propose a methodology for the construction of reference datasets for Online Social Networks and present a case study for the construction of a Twitter dataset for the detection of social bots.
Anais do XII Simpósio Brasileiro de Segurança da Informação e de Sistemas Computacionais (SBSeg 2012)
Este artigo analisa a sensibilidade de preditores de suavização exponencial usados para detectar ... more Este artigo analisa a sensibilidade de preditores de suavização exponencial usados para detectar ataques distribuídos de negação de serviço (DDoS). Comparou-se a capacidade de detecção de dois preditores (EWMA e Holt-Winters) com diferentes configurações e cenários. Foi verificado o desempenho através das taxas de falsos positivos e falsos negativos gerados. Foi inserido ataques em traces reais do MAWILab e em amostras reais de tráfego de backbone da RNP com o intuito de realizar simulações de ataques com diferentes volumes de inundação. As simulações mostram que a otimização de parâmetros dos preditores trazem melhores resultados.
Agent-based models have been an emerging approach in epidemiological modelling, specifically in i... more Agent-based models have been an emerging approach in epidemiological modelling, specifically in investigating the COVID-19 virus. However, there are challenges to its validation due to the absence of real data on specific socioeconomic and cognitive aspects. Therefore, this work aims to present a strategy for updating, verifying and validating these models based on applying the particle swarm optimization algorithm to better model a real case. For such application, this work also presents a new framework based on multi-agents that allowed estimating the evolution of the pandemic, predicting hospital resources, and estimating adaptive population immunization and population density in specific areas. Evaluation metrics such as the data's Shape Factor (SF), Mean Square Error (RMSE), and statistical and sensitivity analyses of the responses obtained were applied for comparison with the real data. The Brazilian municipality of Passa Vinte, located in the State of Minas Gerais (MG), was used as a case study. The model was updated in cumulative cases until the 365th day of the pandemic. The results obtained in the statistical and sensitivity analysis showed similar patterns around the actual data up to the 500th day of the pandemic. Their mean values of SF and RMSE were 0.96 and 7.22, respectively, showing good predictability and consistency, serving as an adequate tool for decision-making in health policies.
Anais do ... Simpósio Brasileiro de Automação Inteligente, 2021
Radio frequency identification systems are used in several applications for the unique recognitio... more Radio frequency identification systems are used in several applications for the unique recognition of objects. Due to the remote communication, malicious agents can read, alter and copy the transmitted information to damage the system. Therefore, researchers have created several protocols to protect these communications employing cryptographic techniques. Recently, Baashirah and Abuzneid proposed a serverless RFID authentication protocol (SLEC) based on elliptic curve cryptography to secure communication in RFID systems. Nevertheless, it has security vulnerabilities and its scalability is faulty. This work presents a comprehensive analysis that discusses the State of the Art of cryptographic applications in RFID systems and points out the SLEC protocol security and scalability issues.
A minimização do consumo de energia em redes Ad-Hoc constitui uma grande preocupação para os admi... more A minimização do consumo de energia em redes Ad-Hoc constitui uma grande preocupação para os administradores desse tipo de rede. Com a disponibilidade cada vez maior de recursos de redes, as operações que envolvem os conceitos de Comando e Controle, sejam civis ou militares, podem cada vez mais se beneficiar desse tipo de estudo. Este trabalho apresenta uma revisão bibliográfica dos principais conceitos de redes de comando e controle, bem como sobre o consumo de energia em redes Ad-Hoc, que são bastante utilizadas nesse tipo de ambiente.
Agent-based models have been an emerging approach in epidemiological modelling, specifically in i... more Agent-based models have been an emerging approach in epidemiological modelling, specifically in investigating the COVID-19 virus. However, there are challenges to its validation due to the absence of real data on specific socioeconomic and cognitive aspects. Therefore, this work aims to present a strategy for updating, verifying and validating these models based on applying the particle swarm optimization algorithm to better model a real case. For such application, this work also presents a new framework based on multi-agents, whose significant contribution consists of forecasting needed hospital resources, population adaptative immunization and reports concerning demographic density, including physical and socioeconomic aspects of a real society in the modelling task. Evaluation metrics such as the data's Shape Factor (SF), Mean Square Error (RMSE), and statistical and sensitivity analyses of the responses obtained were applied for comparison with the real data. The Brazilian municipality of Passa Vinte, located in the State of Minas Gerais (MG), was used as a case study. The model was updated in cumulative cases until the 365th day of the pandemic. The statistical and sensitivity analysis results showed similar patterns around the actual data up to the 500th day of the pandemic. Their mean values of SF and RMSE were 0.96 and 7.22, respectively, showing good predictability and consistency, serving as an adequate tool for decision-making in health policies. Multi-agent-based models have aroused the interest of many researchers in several applications. Its approach consists of a method for analyzing "complex social systems" characterized by multiple interacting parts and may present non-linear behaviours. Policymakers and researchers have applied these models exhaustively, seeking answers to epidemiologic and biological issues. For instance, to investigate the effects of a given pathogen on society and the human body, experimental testing conditions would put the safety of people at risk, creating ethical problems and/or biological disasters. Thus, multi-agent models consist of autonomous agents who work toward goals (as opposed to discrete tasks) in a dynamic environment (where change is the norm), without continuous direct supervision or control, and exhibit a significant degree of flexibility 6. Therefore, the multi-agent approach becomes a reasonable and suitable proposal for modelling due to the variety of effects caused by the Severe Acute Respiratory Syndrome-2 (SARS-CoV-2) virus in the human body and society Corona Virus Disease (COVID-19) spreading. However, it is worth mentioning the following question: how may these models be evaluated and validated? Using multi-agent models to model real-world and social systems has attracted criticism due to the challenges involved in their validation 20. This work studied an intra-state conflict multi-agent-based model to give a balanced perspective on those criticisms. Indeed, multi-agent models for social systems are most useful when the connection between micro-behaviours and macro-behaviours is not well-understood. Another point is when data collection from the real-world system is prohibitively expensive for time or money or if it puts human lives at risk. Despite the criticisms regarding agent-based models, this approach is advantageous when agents are heterogeneous, and the heterogeneity of the agents affects the overall performance of the system. Also, these models provide more detailed information than equation-based models or many other approaches. These agents' interactions are frequently non-linear, changing both spatially and temporally. The emphasis is on modelling, capturing, and replicating new emergent properties in a complex system of individual components that evolve
Anais do XIV Simpósio Brasileiro de Computação Ubíqua e Pervasiva (SBCUP 2022)
Radio frequency identification systems are widely used to uniquely identify objects in many appli... more Radio frequency identification systems are widely used to uniquely identify objects in many applications such as magnetic cards, security tags, and logistic management systems. Despite these advantages provided by the RFID system, there remain a multitude of security concerns related to spoofing and espionage that are all concerned with radio frequency interception. Current research analysis is promising, particularly the work of Ibrahim and Dalkiliç. Their findings are, however, limited by the amount of tags that can be processed—which under certain circumstances can exhaust the server. We designed our new protocol and conducted a performance analysis. When compared to the Ibrahim and Dalkiliç's protocol, our results revealed a drastic reduction in the communication cost that was proportional to the amount of tags authenticated. Once the results were tallied, we modeled our proposed protocol in a discrete event simulation. As a proof of concept, our protocol was then implemente...
Anais do XXV Simpósio Brasileiro de Telecomunicações, 2007
Resumo-Este trabalho estuda os problemas decorrentes da coexistência dos fluxos TCP e UDP em rede... more Resumo-Este trabalho estuda os problemas decorrentes da coexistência dos fluxos TCP e UDP em redes de dados, tendo em vista o observado aumento do volume de tráfego transportado via UDP nosúltimos anos. Nossa propostaé que os fluxos UDP, por não serem cooperativos, sejam penalizados via tarifação de acordo com o impacto causado no tráfego TCP. Algoritmos de controle de admissão e roteamento são propostos de forma a regularem o tráfego UDP minimizando o estrangulamento do TCP e garantindo também a QoS necessária aos fluxos UDP. Resultados da simulação mostram as vantagens da proposta quando comparada com o cenário atual da Internet. Palavras-Chave-qualidade de serviço, coexistência TCP-UDP, controle de congestionamento, controle de admissão, função utilidade Abstract-This work studies the coexistence of TCP and UDP flows in data networks. Our proposal is that UDP flows are penalized, through a dynamic charging scheme, according to the impact caused on TCP traffic. Admission control and routing algorithms are proposed to regulate UDP traffic minimizing TCP starvation and providing the required QoS for UDP flows. Simulation results show the advantage of our proposal when compared to current procedures in the Internet scenario.
Journal of Communications and Networks, Dec 1, 2021
Disruption tolerant networks (DTN) are an evolution of mobile adhoc networks (MANET) working in s... more Disruption tolerant networks (DTN) are an evolution of mobile adhoc networks (MANET) working in scenarios where nodes are sparsely distributed, with low density, connections are intermittent and end-to-end infrastructure is not accessible. Therefore, DTNs are recommended for high latency applications that can last from hours to days. The maritime scenario has characteristics that would justify the use of DTN networks, but the concern with data security is also a relevant aspect in such scenarios. Thus, this paper proposes to evaluate the DTN approach in the maritime Scenario involving warships and helicopters, for sending tactical messages, taking into consideration security aspects at the perimeters where contacts occur. We set up a simulation experiment to compare the performance of Epidemic, Spray and Wait, and Direct Delivery protocols in three scenarios with different sizes. We also propose the application of discriminant analysis as a classification technique to select secure connections to improve the security of the DTN architecture.
Even after nearly two decades of the creation of the first botnet, the detection and mitigation o... more Even after nearly two decades of the creation of the first botnet, the detection and mitigation of their attacks remain one of the biggest challenges faced by researchers and cyber-security professionals. Although there are numerous studies related to botnet detection, estimating how much one method is better than another is still an open problem, mainly because of the difficulty in comparing and reproducing such methods. This work proposes an architecture, implemented with Spark as a high-performance data processing solution, together with VisTrails as a workflow management and data provenance solution, to address this comparability and reproducibility problem in a large-scale environment, as well as a tool, ProvTracker, to analyze and compare the methods results. Another contribution is on the way to couple these two technologies so that intermediary data is maintained available during several partial (re)executions of the experiments involved in each method, minimizing the impact...
Anais Estendidos do XXII Simpósio Brasileiro de Segurança da Informação e de Sistemas Computacionais (SBSeg Estendido 2022)
O BGP e vital para a interligação dos Sistemas Autônomos da Internet, e o número de ataques de se... more O BGP e vital para a interligação dos Sistemas Autônomos da Internet, e o número de ataques de sequestro de prefixos vem aumentando. Entre as soluções discutidas na literatura, o RPKI vem sendo a opção preferencial. O objetivo deste trabalho é o de validar o RPKI, através de testes de robustez a ataques de Prefix Hijacking. Os resultados foram satisfatórios, uma vez que a solução permitiu identificar as rotas não autenticadas. Porém, durante a pesquisa, foi identificado e testado um recurso do RPKI passível de ser usado em ataques, o SLURM FILE. Não foram encontrados trabalhos abordando essa possibilidade, sendo esta a principal contribuicão da dissertação.
Anais do XII Simpósio Brasileiro de Segurança da Informação e de Sistemas Computacionais (SBSeg 2012)
Este trabalho tem por objetivo apresentar uma proposta de arquitetura para um sistema de defesa c... more Este trabalho tem por objetivo apresentar uma proposta de arquitetura para um sistema de defesa cibernética capaz de detecar bots e bloquear a comunicação entre os bots e as botnets. Também é proposto um algoritmo de detecção de bots baseado em grafos de relacionamento. Foram realizados experimentos por meio da análise de registros de consultas DNS com o objetivo de encontrar máquinas suspeitas de serem zumbis. Resultados preliminares mostram que os mecanismos empregados permitem filtrar os registros de DNS e identificar máquinas suspeitas de pertencerem a uma botnet.
This paper presents an application and adaptation of the epidemiological model known as Susceptib... more This paper presents an application and adaptation of the epidemiological model known as Susceptible-Infected- Recovered to the mathematical modeling of the process of message forwarding in a Delay-Tolerant Network scenario char- acterized by epidemic routing. Simulation results are compared to the mathematical model indicating a good fit of the approach.
Anais do XXV Simpósio Brasileiro de Telecomunicações, 2007
Scheduling mechanisms for critical operations over low performance wireless networks use of prior... more Scheduling mechanisms for critical operations over low performance wireless networks use of priorities to guarantee to the most valuable information the available communication resources to accomplish the mission. A traditional way to implement that is to use strict precedence levels, however such naive scheme has several side effects. We propose a multiple criteria decision approach which takes into account several parameters to make a decision. A lexicographic algorithm and an algorithm based on the barrier function are also proposed. Simulation results confirm the advantages on using our approach over traditional methods. Resumo-Os algoritmos de escalonamento de mensagens para operações críticas sobre redes sem fio de baixo desempenho priorizam as mensagens a fim de garantir que a informação mais importante tenha os recursos suficientes para ser enviada. A forma tradicional de se implementar prioridadesé através do emprego de filas de prioridades, contudo este esquema apresenta várias desvantagens. O artigo propõe dois algoritmos multicritério para a realização do escalonamento das mensagens: o primeiro baseado na ordenação lexicográfica e o segundo no uso de funções barreira. Resultados de simulação confirmam o bom desempenho de nossas propostas em comparação com os algoritmos tradicionais.
2018 Workshop on Metrology for Industry 4.0 and IoT, 2018
Reference datasets are databases that guide the development and the evaluation of tools and metho... more Reference datasets are databases that guide the development and the evaluation of tools and methods in several areas of Computer Science. In the field of Information Security, in particular, there is a notable need for tools devoted to detection and classification. Hence, the availability of such datasets is fundamental: the reference dataset is seen as a standard against which a tool must be tested characterize its accuracy. In this sense, the reference dataset is analogous to the classic metrology primary standard, in a sense that it provides the most trustworthy reference against which an object under evaluation can be compared to. It is therefore of great importance to devote efforts to the development of methods that assure the quality of reference datasets. In the present work, we discuss the challenges faced by the currently available datasets and propose directions towards the development of reliable datasets. Finally, we propose a methodology for the construction of reference datasets for Online Social Networks and present a case study for the construction of a Twitter dataset for the detection of social bots.
Anais do XII Simpósio Brasileiro de Segurança da Informação e de Sistemas Computacionais (SBSeg 2012)
Este artigo analisa a sensibilidade de preditores de suavização exponencial usados para detectar ... more Este artigo analisa a sensibilidade de preditores de suavização exponencial usados para detectar ataques distribuídos de negação de serviço (DDoS). Comparou-se a capacidade de detecção de dois preditores (EWMA e Holt-Winters) com diferentes configurações e cenários. Foi verificado o desempenho através das taxas de falsos positivos e falsos negativos gerados. Foi inserido ataques em traces reais do MAWILab e em amostras reais de tráfego de backbone da RNP com o intuito de realizar simulações de ataques com diferentes volumes de inundação. As simulações mostram que a otimização de parâmetros dos preditores trazem melhores resultados.
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Papers by Ronaldo Salles